Many different types of patient monitoring systems require a direct electrical interface to the skin of a patient. In some applications, the direct electrical interface to the patient's skin is for sensing electrical information present at that skin location, while in other applications, the direct electrical interface is for injecting an electrical current signal at that skin location. One example of a device with a skin electrical interface is a patient-worn sensor device that, among other capabilities, may collect patient electrocardiogram (“ECG”) information sensed at the skin of the patient and wirelessly transmit data indicative of the collected ECG information for receipt by another system such as a hospital, clinic or home-based monitoring system. In this wearable ECG sensor device example, the device typically includes firstly an adhesive electrode assembly with multiple individual electrodes wherein the assembly is adapted to be attached to the patient's skin, and secondly a sensor assembly that includes all of the sensing, processing and communication electronics and a power supply for a self-contained sensor-transmitter device. In this case, the electrode assembly provides the direct electrical interface and adhesion to the patient's skin as well as a platform to which the sensor assembly connects and is supported.
Another class of skin electrode assemblies are adapted to be connected by an electrical lead (or in other words, a long wire) to a separate monitoring system, and are intended to be used with the patient “tethered” to the monitoring system. In this electrode assembly example, the patient-worn assembly typically includes an electrode assembly with one or more electrodes adapted to be adhered to the patient's skin and an associated connector assembly with an associated number of contacts to the electrodes of the electrode assembly. The connector assembly is adapted such that a monitoring system lead may be connected to it to provide an electrical connection between the one or more electrodes of the electrode assembly and the sensing and processing circuitry of the separate monitoring system.